[llvm-commits] CVS: llvm/lib/Support/SlowOperationInformer.cpp

[Chris Lattner]

Changes in directory llvm/lib/Support:

SlowOperationInformer.cpp added (r1.1)

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Log message:

New class, useful for command-line interactive programs.


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Diffs of the changes:  (+94 -0)

Index: llvm/lib/Support/SlowOperationInformer.cpp
diff -c /dev/null llvm/lib/Support/SlowOperationInformer.cpp:1.1
*** /dev/null	Tue Dec 30 23:40:12 2003
--- llvm/lib/Support/SlowOperationInformer.cpp	Tue Dec 30 23:40:02 2003
***************
*** 0 ****
--- 1,94 ----
+ //===-- SlowOperationInformer.cpp - Keep the user informed ----------------===//
+ // 
+ //                     The LLVM Compiler Infrastructure
+ //
+ // This file was developed by the LLVM research group and is distributed under
+ // the University of Illinois Open Source License. See LICENSE.TXT for details.
+ // 
+ //===----------------------------------------------------------------------===//
+ // 
+ // This file implements the SlowOperationInformer class for the LLVM debugger.
+ //
+ //===----------------------------------------------------------------------===//
+ 
+ #include "Support/SlowOperationInformer.h"
+ #include "Config/config.h"     // Get the signal handler return type
+ #include <iostream>
+ #include <sstream>
+ #include <signal.h>
+ #include <unistd.h>
+ using namespace llvm;
+ 
+ /// OperationCancelled - This flag is set by the SIGINT signal handler if the
+ /// user presses CTRL-C.
+ static volatile bool OperationCancelled;
+ 
+ /// ShouldShowStatus - This flag gets set if the operation takes a long time.
+ ///
+ static volatile bool ShouldShowStatus;
+ 
+ /// NestedSOI - Sanity check.  SlowOperationInformers cannot be nested or run in
+ /// parallel.  This ensures that they never do.
+ static bool NestedSOI = false;
+ 
+ static RETSIGTYPE SigIntHandler(int Sig) {
+   OperationCancelled = true;
+   signal(SIGINT, SigIntHandler);
+ }
+ 
+ static RETSIGTYPE SigAlarmHandler(int Sig) {
+   ShouldShowStatus = true;
+ }
+ 
+ static sighandler_t OldSigIntHandler;
+ 
+ 
+ SlowOperationInformer::SlowOperationInformer(const std::string &Name)
+   : OperationName(Name), LastPrintAmount(0) {
+   assert(!NestedSOI && "SlowerOperationInformer objects cannot be nested!");
+   NestedSOI = true;
+ 
+   OperationCancelled = 0;
+   ShouldShowStatus = 0;
+ 
+   signal(SIGALRM, SigAlarmHandler);
+   OldSigIntHandler = signal(SIGINT, SigIntHandler);
+   alarm(1);
+ }
+ 
+ SlowOperationInformer::~SlowOperationInformer() {
+   NestedSOI = false;
+   if (LastPrintAmount)
+     std::cout << "\n";
+ 
+   alarm(0);
+   signal(SIGALRM, SIG_DFL);
+   signal(SIGINT, OldSigIntHandler);
+ }
+ 
+ /// progress - Clients should periodically call this method when they are in
+ /// an exception-safe state.  The Amount variable should indicate how far
+ /// along the operation is, given in 1/10ths of a percent (in other words,
+ /// Amount should range from 0 to 1000).
+ void SlowOperationInformer::progress(unsigned Amount) {
+   if (OperationCancelled) {
+     std::cout << "\n";
+     LastPrintAmount = 0;
+     throw "While " + OperationName + ", operation cancelled.";
+   }
+ 
+   // If we haven't spent enough time in this operation to warrant displaying the
+   // progress bar, don't do so yet.
+   if (!ShouldShowStatus)
+     return;
+ 
+   // Delete whatever we printed last time.
+   std::string ToPrint = std::string(LastPrintAmount, '\b');
+ 
+   std::ostringstream OS;
+   OS << "Progress " << OperationName << ": " << Amount/10 << "." << Amount % 10
+      << "%";
+ 
+   LastPrintAmount = OS.str().size();
+   std::cout << ToPrint+OS.str() << std::flush;
+ }